The present invention relates to an apparatus for maintenance of railroad beds. Specifically, it relates to a tamping apparatus and related tamping tool.
In the maintenance of road beds of railroads, the ballast must be periodically stabilized. Specifically, the rocks which make up the ballast are vibrated to get them into a compact stable state. Additionally, ballast should be pushed under the cross ties of the road bed in order to insure a stable support for the cross ties.
Various tamping machines have been used. Generally, such machines are rail vehicles which travel to a part of the road bed where tamping is required. Tamping tools are then lowered and vibrate into the ballast until in position where the tamping tools are moved to squeeze ballast under a cross tie. Specifically, tamping tools are disposed with paddles on their lower ends, the paddles being on opposite sides of a tie and below the level of the tie. The paddles are then pushed together to compress ballast under the tie, this being known as the squeeze in or squeeze position.
Prior U.S. Pat. No. 4,501,200 of Anthony Delucia, one of the inventors herein, describes a TAMPING TOOL RETAINER having an advantageous manner of connecting a tamping tool to a tool holder.
Standard tamping vibrator units have a width which makes it difficult or impossible to use them in tamping ballast at some locations around rail switches.
For switches, one could use two separate vibrators for opposite sides of a tie, but this might require two separate hydraulic or other motors to drive the corresponding front and back tamping tool holders associated with the respective front and back vibrator units. A two motor arrangement introduces additional costs and requires extra space for the second motor. Further, a two motor arrangement makes it difficult or impossible to coordinate the vibration of one unit with the vibration of the other unit.
Vibrator units often have required relatively complex arrangements in order to provide both the vibration supplied to the tamping tool in order to ease its insertion to the appropriate depth in the ballast and to provide the squeeze in movement.
Many vibrator units have tamping tool holders wherein removal and insertion of a tamping tool may require access to bolts, nuts, or other fasteners which are in difficult to access locations. In other words, removal or insertion of an old or replacement tamping tool into the holder may be difficult. In corresponding fashion, many tamping tool designs require bolting in a difficult to access location where clearance for use of a wrench or other tool is quite limited and/or visual observation is difficult.